渐进性咬合紊乱对大鼠髁突软骨中骨形成蛋白2表达的影响

目的：探讨渐进性咬合紊乱所致大鼠髁突软骨改建中骨形成蛋白2（BMP-2）的变化情况及其意义。方法：建立幼年和成年大鼠渐进性咬合紊乱模型,应用免疫组化SABC法检测大鼠髁突软骨中BMP-2的表达变化,并作图像分析和统计学处理。结果：幼年和成年实验组大鼠左右侧髁突软骨中BMP-2的表达差异无统计学意义。与对照组相比,幼年和成年实验组中BMP-2的表达于实验4周时均低于对照组（P〈0.01）,之后出现回升,8周时两组均高于对照组（P〈0.05）。不同时间点比较,幼年与成年实验组中BMP-2的表达在2~8周的时间内均出现先降低再增高的趋势。结论：BMP-2参与了髁突软骨随咬合变化而发生的改建活动。

Effect of Gradually Induced Occlusal Disorders on the Expression of BMP-2 of Condylar Cartilage in Rats

Objective: To study the effect of gradually induced occlusal disorders on the expression of BMP-2 of condylar cartilage. Methods: Young and adult female Sprague-Dawley rats were divided randomly into 4 experimental groups and 4 normal control groups with 3 rats in every group. For experimental rats, the elastic rubbers were inserted between the first and second molar in the left upper side and right lower side to form the disordered occlusion. For normal rats, they were not treated. 2, 4, 6, 8 weeks after treatment respectively ,three rats of each group were killed under anaesthesia. Bilateral temporomandibular joints of each rat were removed and stained with monoclone antibody of BMP-2. The expression of BMP-2 in condylar cartilage was detected by half-quantity immunohistochemical analysis. Results: No difference of the expression of BMP-2 in right and left condylar cartilage was found, no matter in young or adult experimental rats. Compared with the control group, lower expression of BMP-2 in both young and adult experimental groups were found 4 weeks after the treatment (P<0.01). Then, the expression of BMP-2 was increasing. 8 weeks after the treatment, the expression of BMP-2 in both groups were higher than their control groups (P<0.05). After the treatment, the expression of BMP-2 in both young and adult experimental groups firstly decreased and then increased. Conclusion: The gradually induced occlusal disorders may lead to downgrade and then upgrade of the expression of BMP-2 in condylar cartilage, which suggests that BMP-2 may take part in the procedure of remodeling activities of condylar cartilage.